Step-by-Step Introduction of Silazane Moieties at Ruthenium: Different Extents of Ru–H–Si Bond Activation
Résumé
The coordination of pyridine-2-amino(methyl)dimethylsilane ligands to ruthenium has afforded access to a family of novel complexes that display multicenter Ru–H–Si interactions according to the number of incorporated ligands. The new complexes Ru[κ-Si,N-(SiMe2)N(Me)(C5H4N)](η4-C8H12)(η3-C8H11) (1), Ru2(μ-H)2(H)2[κ-Si,N-(SiMe2)N(Me)(C5H4N)]4 (2), and Ru(H)[κ-Si,N-(SiMe2)N(Me)(C5H4N)]3 (3) were isolated and fully characterized. The complexes exhibit different degrees of Si–H activation: complete Si–H cleavage, secondary interactions between the atoms (SISHA), and η2-Si–H coordination. Reversible protonation of 3 leading to the cationic complex [RuH{(η2-H-SiMe2)N(Me)κ-N-(C5H4N)}{κ-Si,N-(SiMe2)N(Me)(C5H4N)}2]+[BArF4]− (5) was also demonstrated. The coordination modes in these systems were carefully studied with a combination of X-ray and neutron diffraction analysis, DFT geometry optimization, and multinuclear NMR spectroscopy.